Learning the Language of Biological Sequences

International audienceLearning the language of biological sequences is an appealing challenge for the grammatical inference research field.While some first successes have already been recorded, such as the inference of profile hidden Markov models or stochastic context-free grammars which are now part of the classical bioinformatics toolbox, it is still a source of open and nice inspirational problems for grammatical inference, enabling us to confront our ideas to real fundamental applications. As an introduction to this field, we survey here the main ideas and concepts behind the approaches developed in pattern/motif discovery and grammatical inference to characterize successfully the biological sequences with their specificities

Recent Methods for RNA Modeling Using Stochastic Context-Free Grammars

Stochastic context-free grammars (SCFGs) can be applied to the problems of folding, aligning and modeling families of homologous RNA sequences. SCFGs capture the sequences' common primary and secondary structure and generalize the hidden Markov models (HMMs) used in related work on protein and DNA. This paper discusses our new algorithm, Tree-Grammar EM, for deducing SCFG parameters automatically from unaligned, unfolded training sequences. Tree-Grammar EM, a generalization of the HMM forward-backward algorithm, is based on tree grammars and is faster than the previously proposed inside-outside SCFG training algorithm. Independently, Sean Eddy and Richard Durbin have introduced a trainable "covariance model" (CM) to perform similar tasks. We compare and contrast our methods with theirs

On interaction motif inference from biomolecular interactions: Riding the growth of the high throughput sequential and structural data

Ph.DDOCTOR OF PHILOSOPH